On Jun 20, 2:17*pm, wrote:
* * * * *We have some 172s and a 182 and a couple of Citabrias. These
airplanes all came with electromechanical voltage regulators, where a
small electromagnet pulls open the field current contacts to limit
alternator output. The 172s and 182 are all 1970s models and ran for
years and years and thousands of hours on those primitive make-and-
break buzzer-type regulators, and when they did quit we'd buy new
ones.
* * * * * *Now, the manufacturer makes regulators that look the same
and have the same part number, but the make-break contact setup has
been replaced with an electronic control circuit. No moving parts. And
those regulators last as little as a week and no more than a year or
two and cost every bit as much as the old style. What did we gain
there?

A poorly designed switching regulator, a component so common in
electrical design that it is often given as a project to
undergraduates in electrical engineering [http://www.rason.org/
Projects/swregdes/swregdes.htm]. You could go over to
sci.electronics.design and ask the other EE's what they think about
botching a switching regulator and see what they say.

* * * * * *We fly in Canada where it can get really, really cold. The
epoxy cases on computer chips or transistor cases contract and crack
at -40 and moisture from the air gets in there and shorts them and
they're dead. Finished. This can happen when the unit is parked
outside, as they often are. Next time the pilot goes to use his
airplane the radio doesn't want to work right because the synthesized
tuner, which replaced a bank of switched crystals, is wandering all
over the place because its frequency counter chip is pooched. What did
we gain there? That radio weighs as much as the old crystal unit did
and lasted one fifth as long as the old one. What else would we use to
encapsulate a chip that wouldn't shrink and crack at -40? The LCD
displays on these things quit at -25 degrees. The liquid crystal
freezes. Useless. Narco uses a special gas discharge display in many
of their avionics, and that stupid thing burns out regularly. $350 for
each side of a NavComm. The old mechanically tuned radios keep on
going. What did we gain there?

Bad designs. I have a spare deactivated cell phone that I keep in my
Jeep for 911 emergencies. It sat in my Jeep for years. Every time I
have connected it to power outlet, it works, without a problem. True,
-25 is extreme, but not so extreme that reliable components could not
be made for those temperature. The point here is that it is not the
devices fault. If it breaks, it is because it was not engineered
properly for that environment.

* * * * * I'm not against electronics. I've worked on electronic
devices since I was 14 years old, which was 41 years ago. It's just
that the "advances" we've been sold aren't ready yet and cost MORE
than the older ones did and are LESS reliable.

I think this happens in aviation (and automotive industry in general).
This is what I meant about inter-discipline engineering. The Dean at
my university had launched a program that essentially asked, for
example, the mechanical engineering department to allow the electrical
engineers more freedom in designing those aspects of ME devices that
required electronics, and vice versa, the idea being that, if the EE's
are allowed to do the EE part, and the ME's are allowed to do the ME
part, the the overall system will be cheaper, more reliable, etc,
because each department would be exercising their natural
competencies. There were multiple programs like this at my
university, so many that one would have to conclude that this type of
development was not occurring.

We really haven't moved
ahead much at all and I would not trust my primary flight controls to
a single set of FBW controls. Airliners use three systems, just like
heavy trucks have three separate braking systems (but only one drum/
shoe per wheel) and such redundancy adds a lot of cost and weight.
Those 1/8" cables and their pulleys are going to be around for a long
time yet, believe me, and it's not because we don't want electronics,
it's because we can't trust them that much. My Power Mechanics teacher
in high school told us kids that 90% of all car problems would be
electrical, and in those many years since he's been proven right over
and over again.

Well, as you mentioned, change is going to happen some day.

What will change to allow these things to happen? It most likely will
not be new materials. Faults in electronics are generally due bad
design of the system, not the components themselves. What will have
changed when the day comes where you can trust the system?

[snipped]

* * * * * *Stop dreaming about alternate propulsion methods and fancy
FBW systems and go invent and build them and if they make sense
they'll sell and you'll become rich and famous. Aviation is as market-
driven as anything else, and we're not resistant to innovation that
saves us money or makes us safer. But we WON'T buy something that
doesn't work as well as what we have now. Period.

Well, something that makes sense would be something that is lighter,
cheaper, easier to fix, etc than what we have, which would mean it
would be imprudent, to say, spend $50,000 on a base plane, and add a
$5000 of extra equipment to it. That would not make sense.

In any case, my focus is only in the propulsion system. If that
failed, there would be no point for me, personally, to continue, as it
is very difficult, if not impossible, to improve upon the tractor
model to satisfy requirements outlined by CAFE/PAV.

-Le Chaud Lapin-